1. Field of the Invention
The field of the invention is novel polymeric bromine-containing phosphoramidate polyols novel intermediates and methods for use in synthesizing such novel polyols and use thereof as co-reactive flame retardants in the preparation of polyurethanes.
2. Background of the Invention
Incorporation of phosphorus or halogen compounds to impart flame resistance to an organic resin is well known in the art. It is also well known in the art that incorporation of both phosphorus and halogen into the polymer produces a synergistic effect, and furthermore, that bromine compounds are more effective flame reducing agents than the corresponding chlorine analogs.
Numerous phosphorus and halogen compositions have been disclosed as flame retardants for organic resins. These are of two general types: additive and reactive flame retardants. The reactive type flame retardants are those which possess at least two reactive sites through which they are chemically bound to the polymer backbone. These are usually superior to the additive type flame retardants, for they will not leach out, evaporate or sublime out of the polymer substrate during processing or use, thus leaving the polymer surface unprotected and often badly degraded.
Simple phosphoramidates have been disclosed and claimed as flame retardants. Thus U.S Pat. No. 2,971,929 issued Feb. 14, 1961 in the name of Glade discloses monomers of the type: ##EQU1## as flame retardants for textile materials. Also, British Pat. Nos. 835,581 and 585,582 disclose ##EQU2## type structures as useful flame retardants for textiles.
German Patent 1,163,018 discloses bis(2-chloroethoxy)-phosphoramide, ##EQU3## as a flame retardant for polyurethanes.
All of the above are simple monomeric molecules which are additive type materials. They, therefore, completely differ in substance and scope from the materials of this invention.
On the other hand, U.S. Pat. Nos. 3,256,249 and 3,335,129 issued in the name of Vogt et al on June 14, 1966 and Aug. 8, 1967, respectively, disclose certain phosphoramidate polyols as reactive flame retardants for polyurethane resins. These are prepared by treating polyols with amidophosphorochloridates according to the equations: ##EQU4## These phosphoramide polyols are derived from different starting materials and, therefore, are quite different chemically from the compositions of my invention. Just as important, these do not contain bromine atoms and therefore are inferior in activity to the compounds of the present invention.
U.S. Pat. Nos. 3,597,503 granted on Aug. 3, 1971 in the name of Wilson et al discloses monomeric cyclic phosphoroamidates which are made by reacting a diol with a phosphoryl trihalide to form a product, reacting this product with ammonia or a primary or secondary amine to form a second product, and subsequently reacting this second product with an aldehyde or an epoxide. The final products are said to be reactive flame retardants for polyurethanes. None of the products disclosed in this patent remotely resembles the polymeric bromide-containing phosphoroamidate polyols of the present invention.